The invention relates to a method for isolating hydrogen sulphide from coke-oven gas with the subsequent recovery of elemental sulphur in a Claus plant. The hydrogen sulphide is eliminated from the coke-oven gas by gas washing using an absorption liquid. During the regeneration of the loaded absorption liquid, hydrogen sulphide is accumulated in concentrated form and is fed to the Claus plant. Said Claus plant comprises a Claus boiler, a waste-heat boiler, in addition to a reactor, which forms an additional catalyst stage. According to the invention, the Claus plant is operated with a single reactor, which operates at a working temperature of below 250° C. The process gas that exits the reactor is returned after the deposition of elemental sulphur with a non-reacted residual concentration of hydrogen sulphide to the coke-oven gas that is to be cleaned, prior to the gas washing stage.